(1) Field of the Invention
The present invention relates to a system, and method for utilizing such a system, for detecting and isolating faults in the operation of a device. More specifically, the present invention relates to a system, and method for utilizing such a system, for detecting faults in engines, such as gas turbine engines.
(2) Description of Related Art
A pivotal requirement for achieving accurate performance tracking of a gas turbine engine, in real time during flight operation, is the application of high fidelity models that impose low computational burdens. Although high fidelity physics based models of a gas turbine engine can be developed, they tend to become too computationally demanding to meet the accuracy requirements necessary to assemble a Fault Detection and Isolation (FDI) system. Likewise, empirical models suffer from a similar problem in that they typically require excessive memory and computational burden. A practical solution to this problem is to employ a mixture of modeling methodologies thereby creating a hybrid engine model that incorporates both physics-based and empirical components.
Hybrid systems have been developed for the purpose of tracking performance deterioration (such as changes in engine module efficiency and flow parameters) in individually monitored gas turbine engines. Such systems employ a physics-based component and use an empirical element to model the difference between the physics model and the monitored engine. Hybrid (engine) models and attendant performance estimation algorithms have been developed for tracking module performance shifts (deltas) in a real-time environment for use in such systems.
What is needed is an extension of the principle used in prior art systems to include the detection and isolation of engine faults other than, and in addition to, Module performance shifts. These include faults in measurement instrumentation (measurement error) as well as engine system faults such as variable geometry actuation faults, cooling flow faults, engine bleed valve faults, or any fault resulting in non-nominal engine operation.